“A Google search would have revealed everything before the opening credits rolled on episode one, but this was all about beautifully modulated storytelling, less whodunnit more howtheygothim. Through a mixture of dogged police work and some luck, it transpired, which made for another gripping viewing experience.” “This final stretch tried to ramp up the tension with an interrogation scene and a race against time to find a crucial bit of forensic evidence. But there was nothing here to keep us riveted, not even Keith Allen’s skilful turn as the nasty little killer. This was otherwise a useful corrective to shows that present an unrealistic picture of police work.”